/*
 * Copyright 2023 Hazelcast Inc.
 *
 * Licensed under the Hazelcast Community License (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://hazelcast.com/hazelcast-community-license
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.hazelcast.jet.sql.impl.opt.logical;

import com.hazelcast.jet.sql.impl.opt.OptUtils;
import com.hazelcast.sql.impl.schema.map.PartitionedMapTable;
import org.apache.calcite.plan.RelOptRule;
import org.apache.calcite.plan.RelOptRuleCall;
import org.apache.calcite.plan.RelOptTable;
import org.apache.calcite.rex.RexNode;

import static com.hazelcast.jet.sql.impl.opt.Conventions.LOGICAL;

/**
 * Planner rule that matches single key, constant expression,
 * {@link PartitionedMapTable} UPDATE.
 * <p>For example,</p>
 * <blockquote><code>UPDATE map SET this = 2 WHERE __key = 1</code></blockquote>
 * <p>
 * Such UPDATE is translated to optimized, direct key {@code IMap} operation
 * which does not involve starting any job.
 */
final class UpdateByKeyMapLogicalRule extends RelOptRule {

    static final RelOptRule INSTANCE = new UpdateByKeyMapLogicalRule();

    private UpdateByKeyMapLogicalRule() {
        super(
                operandJ(
                        TableModifyLogicalRel.class, LOGICAL, modify -> !OptUtils.requiresJob(modify) && modify.isUpdate(),
                        operandJ(
                                FullScanLogicalRel.class,
                                null,
                                scan -> OptUtils.hasTableType(scan, PartitionedMapTable.class),
                                none()
                        )
                ),
                UpdateByKeyMapLogicalRule.class.getSimpleName()
        );
    }

    @Override
    public void onMatch(RelOptRuleCall call) {
        TableModifyLogicalRel update = call.rel(0);
        FullScanLogicalRel scan = call.rel(1);

        RelOptTable table = scan.getTable();
        RexNode keyCondition = OptUtils.extractKeyConstantExpression(table, update.getCluster().getRexBuilder());
        if (keyCondition != null) {
            UpdateByKeyMapLogicalRel rel = new UpdateByKeyMapLogicalRel(
                    update.getCluster(),
                    OptUtils.toLogicalConvention(update.getTraitSet()),
                    table,
                    keyCondition,
                    update.getUpdateColumnList(),
                    update.getSourceExpressionList()
            );
            call.transformTo(rel);
        }
    }
}
